1109209 has 4 divisors (see below), whose sum is σ = 1111860. Its totient is φ = 1106560.

The previous prime is 1109197. The next prime is 1109219. The reversal of 1109209 is 9029011.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9029011 = 43 ⋅209977.

It can be written as a sum of positive squares in 2 ways, for example, as 299209 + 810000 = 547^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 1109209 - 2⁹ = 1108697 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1109209.

It is not an unprimeable number, because it can be changed into a prime (1109219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 544 + ... + 1585.

It is an arithmetic number, because the mean of its divisors is an integer number (277965).

2^1109209 is an apocalyptic number.

It is an amenable number.

1109209 is a deficient number, since it is larger than the sum of its proper divisors (2651).

1109209 is an equidigital number, since it uses as much as digits as its factorization.

1109209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 1109209 is about 1053.1899163968. The cubic root of 1109209 is about 103.5152800921.

The spelling of 1109209 in words is "one million, one hundred nine thousand, two hundred nine".